Means of Egress
Domain focus
Means of Egress tests occupant load, egress width, number of exits, travel distance, common path, door and stair requirements, and exit discharge. The exam expects you to calculate occupant load first and then apply the component requirements in sequence.
Core rules
- §1004 occupant load is based on Table 1004.5 factors; gross area is used for most occupancies, net for others.
- §1005 egress width: 0.2 inch per occupant for stairs, 0.15 inch per occupant for other egress components, with minimums.
- §1006 number of exits: generally two exits are required when occupant load is 50 or more, with exceptions; remote distance rules apply.
- §1017 travel distance limits vary by occupancy and sprinkler protection.
- §1010 doors: clear width, swing direction, hardware, and opening force.
- §1011 stairs: riser and tread dimensions, handrails, headroom, and vertical clearance.
- §1013 guards and §1015 illumination and emergency lighting.
Worked example
A 2,000 sf Group A assembly area without fixed seating has an occupant load factor of 15 sf per occupant, so 2,000 / 15 = 133 occupants. Because 133 exceeds 49, at least two exits are required. The required egress width through the corridor is 133 x 0.15 inch = 19.95 inches, so a 36-inch corridor is adequate for width, but the two exits must still be remote from each other. The designer must provide two exits with the required separation; a wider single corridor does not satisfy the number-of-exits rule.
Traps
Do not use net area when the table requires gross area. Do not forget fixed seating in occupant load. Do not measure travel distance to the nearest exit door if the code requires measurement along the natural path. Do not ignore door swing in the direction of egress for 50 or more occupants. Do not omit the exit discharge.